The present study dealt with the implantological decision-making process in the edentulous mandible. The objective was to determine the influence of various factors such as "age", "readiness to involvement", "co-morbidity" and "smoking" on the treatment decision in the narrow atrophied edentulous mandible by using case vignettes. The response rate of almost 47% achieved can be classified as high, especially against the background that no incentives were provided in the study. Mehlkop and Becker23 stated in their study that a response rate of approximately 28% was to be expected if the respondents did not receive any reward and of approx. 52% if an incentive was provided.
Every physician develops clinical routines in the course of his or her professional life, which he or she uses in his or her practice to provide good and reliable care.24 These routines concern diagnostics and decision-making as well as the performance of the actual medical procedure. In the decision-making process, the physician has the duty to identify technically responsible ways to solve the clinical problem that exists on the patient's side. Often there are several options for achieving this goal. Clinical case vignettes offer a practicable option for determining the decision making of a large number of physicians. Here case vignettes have a comparable validity as a systematic medical record evaluation or an evaluation with standardized patients18,20−22
In the present study, both case vignettes included the therapy options of bone split, bone block, the use of bone substitute material and bone resection. In addition, there was the option to generally approve or reject therapy in the given case. Bone block and bone split are the more complex therapy forms of the four options. In addition, block transplantation with autologous bone always requires a donor region, which leads to additional trauma with chances of increased postoperative symptoms and increased surgical risk.25 While bone resection usually can be done with simultaneous placement of implants, bone block transplantation often requires a second operation a few months later.6,26,27
With case vignette 1 it could be shown that more than 80% of the surgeons approved of a therapy for the narrow atrophic edentulous mandible. Altogether, bone resection was preferred by a large majority over any other treatment option. In all four combinations of this case vignette, bone resection was the "therapy of my choice". The use of bone substitute material followed at a considerable distance. This seems to be reasonable, since both techniques usually allow simultaneous placement of implants and the surgical risk seems to be acceptable. Bone block transplants and bone split, on the other hand, were rejected with high percentages and had only few supporters. This could be explained by the reasons mentioned above.
Case vignette 2 showed a similar, but even more pronounced pattern. A therapy was somewhat more clearly advocated and bone resection was even more popular. Bone substitute material followed at a substantial distance. Bone block transplants and bone split were rejected even more strongly.
However, patient age was significantly associated with bone block and bone substitute material in vignette 1. With regard to bone block transplants, it can be assumed that patients of higher age are more likely to suffer from postoperative discomfort and should be spared a longer treatment period. Smoking also led to a significantly higher refusal of treatment. This is comprehensible, as tobacco consumption leads to higher infection rates and in the long term tends to promote periimplantitis.28,29 The comparison of the determinants “age” and “smoking” showed that age had a lower influence on the decision to recommend a therapy than smoking. The participants therefore decided not to do "age-rationing", but to take into account the oral health status, which experience has shown to be associated with smoking. Reasons for this could be that placing implants in the lower jaw is successful in the long term even at an advanced age30 and moreover higher patient satisfaction can be achieved.31
Case vignette 2 showed that the patients' anxiety had no correlation with the treatment methods chosen. An already performed radiotherapy treatment in the neck area was only significantly correlated with bone split. This option was only rarely chosen, while bone resection was the therapy of choice for most of the specialists. As mentioned above, bone resection offers the possibility of simultaneous placing implants and avoids augmentation procedures. Therefore, bone resection is particularly suitable for anxious patients and avoids a complex procedure in post-radiation conditions. Both determinants did not, however, lead to the general exclusion of surgical treatment.
The most serious complication of radiotherapy is radiation necrosis of the bone.32 This is an irreversible, progressive devitalization of the irradiated bone. The clinical manifestation may be pain, orofacial fistulas, exposed necrotic bone, pathological fractures and putrid infections.33 For these reasons, radiotherapy is actually considered a risk factor.34 The fact that many surgeons were nevertheless in favor of surgery may be due to the fact that the mandible was not in the direct radiation field.